Substituted pyridylpyrimidines, their preparation and their use

ABSTRACT

##STR1## Substituted pyridylpyrimidines have formula (I), in which A and Ar have the meaning given in the test of the description. Also disclosed are their preparation, their use and new initial products. The compounds having formula (I) may be prepared from appropriate salts of 2-pyridylamidine with appropriate enamines; said enamines are also new and disclosed by the invention, and may be prepared from appropriate ketones with appropriate formaldehyde derivates.

This application is a 371 of PCT/EP92/00311filed Feb 13, 1992.

The invention relates to novel substituted pyridylpyrimidines, to aprocess for their preparation, to their use as pesticides, and to novelintermediates.

It has been disclosed that certain substituted pyridylpyrimidines suchas, for example, the compound2-(6-phenyl-2-pyridyl)-4-chloro-6-methylpyrimidine or the compound2-(6-methyl-2-pyridyl)-4-(2-methylphenyl)-pyrimidine or the compound2-(6-methyl-2-pyridyl)-4-hydroxy-6-phenylpyrimidine have fungicidalproperties (cf., for example, EP 259,139 or EP 270,362). However, theactivity of these previously known compounds is not entirelysatisfactory in all fields of application, in particular when lowamounts and concentrations are applied.

Novel substituted pyridylpyrimidines of the general formula ( I )##STR2## in which A represents a radical of the formula ##STR3## where Rin each case represents alkyl,

X represents oxygen or sulphur and

Ar represents optionally substituted phenyl, have been found.

Furthermore, it has been found that the novel substitutedpyridylpyrimidines of the general formula (I), ##STR4## in which Arepresents a radical of the formula ##STR5## where R in each caserepresents alkyl,

X represents oxygen or sulphur and

Ar represents optionally substituted phenyl, are obtained when2-pyridylamidine salts of the formula (II) ##STR6## in which Yrepresents the anion of an inorganic mineral acid, are reacted withenamines of the formula (III) ##STR7## in which Ar and A have theabovementioned meaning, if appropriate in the presence of a diluent andif appropriate in the presence of a reaction auxiliary.

Finally, it has been found that the novel substituted pyridylpyrimidinesof the general formula (I) have a good activity against pests.

Surprisingly, the substituted pyridylpyrimidines of the general formula(I) according to the invention show a markedly improved activity, forexample against phytopathogenic fungi, when compared with thesubstituted pyridylpyrimidines which are known from the prior art, forexample the compound 2-(6-phenyl-2-pyridyl)-4-chloro-6-methylpyrimidineor the compound 2-(6-methyl-2-pyridyl)-4-(2-methylphenyl)-pyrimidine orthe compound 2-(6-methyl-2-pyridyl)-4-hydroxy-6-phenyl-pyrimidine, whichare similar compounds chemically and from the point of view of theiraction.

Formula (I) provides a general definition of the substitutedpyridylpyrimidines according to the invention.

Preferred compounds of the formula (I) are those in which

A represents a radical of the formula ##STR8## where R in each caserepresents straight-chain or branched alkyl having 1 to 4 carbon atoms,

X represents oxygen or sulphur and

Ar represents phenyl which is optionally monosubstituted topentasubstituted by identical or different substituents, suitablesubstituents being: halogen, cyano, nitro, in each case straight-chainor branched alkyl, alkoxy or alkylthio, in each case having 1 to 4carbon atoms, in each case straight-chain or branched halogenoalkyl,halogenoalkoxy or halogenoalkylthio, in each case having 1 to 4 carbonatoms and 1 to 9 identical or different halogen atoms, in each casestraight-chain or branched alkoxycarbonyl or alkoxyiminoalkyl, in eachcase having 1 to 4 carbon atoms in the individual alkyl moieties, orphenyl which is optionally monosubstituted to pentasubstituted byidentical or different substituents from the series comprising halogenand/or straight-chain or branched alkyl having 1 to 4 carbon atoms.

Particularly preferred compounds of the formula (I) are those in which

A represents a radical of the formula ##STR9## where R in each caserepresents methyl or ethyl,

X represents oxygen or sulphur and

Ar represents phenyl which is optionally monosubstituted totrisubstituted by identical or different substituents, suitablesubstituents being: fluorine, chlorine, bromine, cyano, nitro, methyl,ethyl, n- or i-propyl, n-, i-, s- or t-butyl, methoxy, ethoxy, n- ori-propoxy, methylthio, trifluoromethyl, trifluoromethoxy,trifluoromethylthio, methoxycarbonyl, ethoxycarbonyl,methoxyiminomethyl, ethoxyiminomethyl, methoxyiminoethyl,ethoxyiminoethyl, or phenyl which is optionally monosubstituted totrisubstituted by identical or different substituents from the seriescomprising fluorine, chlorine, bromine, methyl and/or ethyl.

Very particularly preferred compounds of the formula (I) are those inwhich

A represents a radical of the formula ##STR10## and Ar represents phenylwhich is optionally monosubstituted or disubstituted by identical ordifferent substituents, suitable substituents being: fluorine, chlorine,bromine, cyano, nitro, methyl, ethyl, n- or i-propyl, n-, i-, s- ort-butyl, methoxy, ethoxy, n- or i-propoxy, methylthio, trifluoromethyl,trifluoromethoxy, trifluoromethylthio, methoxycarbonyl orethoxycarbonyl.

In addition to the compounds mentioned in the Preparation Examples, thefollowing substituted pyridylpyrimidines of the general formula (I) maybe mentioned individually:

    __________________________________________________________________________     ##STR11##                           (I)                                      A        Ar         A        Ar                                               __________________________________________________________________________     ##STR12##                                                                              ##STR13##                                                                                ##STR14##                                                                              ##STR15##                                        ##STR16##                                                                              ##STR17##                                                                                ##STR18##                                                                              ##STR19##                                        ##STR20##                                                                              ##STR21##                                                                                ##STR22##                                                                              ##STR23##                                        ##STR24##                                                                              ##STR25##                                                                                ##STR26##                                                                              ##STR27##                                        ##STR28##                                                                              ##STR29##                                                                                ##STR30##                                                                              ##STR31##                                        ##STR32##                                                                              ##STR33##                                                                                ##STR34##                                                                              ##STR35##                                        ##STR36##                                                                              ##STR37##                                                                                ##STR38##                                                                              ##STR39##                                        ##STR40##                                                                              ##STR41##                                                                                ##STR42##                                                                              ##STR43##                                        ##STR44##                                                                              ##STR45##                                                                                ##STR46##                                                                              ##STR47##                                        ##STR48##                                                                              ##STR49##                                                                                ##STR50##                                                                              ##STR51##                                        ##STR52##                                                                              ##STR53##                                                                                ##STR54##                                                                              ##STR55##                                        ##STR56##                                                                              ##STR57##                                                                                ##STR58##                                                                              ##STR59##                                        ##STR60##                                                                              ##STR61##                                                                                ##STR62##                                                                              ##STR63##                                        ##STR64##                                                                              ##STR65##                                                                                ##STR66##                                                                              ##STR67##                                        ##STR68##                                                                              ##STR69##                                                                                ##STR70##                                                                              ##STR71##                                        ##STR72##                                                                              ##STR73##                                                                                ##STR74##                                                                              ##STR75##                                        ##STR76##                                                                              ##STR77##                                                                                ##STR78##                                                                              ##STR79##                                        ##STR80##                                                                              ##STR81##                                                                                ##STR82##                                                                              ##STR83##                                        ##STR84##                                                                              ##STR85##                                                                                ##STR86##                                                                              ##STR87##                                        ##STR88##                                                                              ##STR89##                                                                                ##STR90##                                                                              ##STR91##                                        ##STR92##                                                                              ##STR93##                                                                                ##STR94##                                                                              ##STR95##                                        ##STR96##                                                                              ##STR97##                                                                                ##STR98##                                                                              ##STR99##                                        ##STR100##                                                                             ##STR101##                                                                               ##STR102##                                                                             ##STR103##                                       ##STR104##                                                                             ##STR105##                                                                               ##STR106##                                                                             ##STR107##                                       ##STR108##                                                                             ##STR109##                                                                               ##STR110##                                                                             ##STR111##                                       ##STR112##                                                                             ##STR113##                                                                               ##STR114##                                                                             ##STR115##                                       ##STR116##                                                                             ##STR117##                                                                               ##STR118##                                                                             ##STR119##                                       ##STR120##                                                                             ##STR121##                                                                               ##STR122##                                                                             ##STR123##                                       ##STR124##                                                                             ##STR125##                                                                               ##STR126##                                                                             ##STR127##                                       ##STR128##                                                                             ##STR129##                                                          __________________________________________________________________________

If, for example, 2-pyridylamine hydrochloride and1-dimethylamino-4,4-dimethyl-5-(4methylphenyl)-pent-1-en-3-one are usedas starting compounds, the course of the reaction of the processaccording to the invention can be represented by the following equation:##STR130##

Formulation (II) provides a general definition of the 2-pyridylamidinesalts required as starting substances for carrying out the processaccording to the invention. In this formula (II), Y preferablyrepresents a halide anion or a hydrogen sulphate anion, in particular achloride anion, a bromide anion or a hydrogen sulphate anion. Yparticularly preferably represents a chloride anion.

The 2-pyridylamidine salts of the formula (II) are known (cf., forexample, U.S. Pat. No. 4,018,770 or J. Am. Chem. Soc. 107, 5745-5754[1985] or J. Med. Chem. 33, 1230-1241 [1990]).

Formula (III) provides a general definition of the enamines furthermorerequired as starting substances for carrying out the process accordingto the invention. In this formula (III), Ar and A preferably representthose radicals which have already been mentioned in connection with thedescription of the substances of the formula (I) according to theinvention as being preferred for these substituents.

The enamines of the formula (III) were hitherto unknown and are also asubject of the invention.

They are obtained when ketones of the formula (IV). ##STR131## in whichAr and A have the abovementioned meaning, are reacted with formaldehydederivatives of the formula (V), ##STR132## in which Z represents aradical --O--R¹ or a radical ##STR133## and R¹, R² and R³ independentlyof one another in each case represent alkyl, in particularstraight-chain or branched alkyl having 1 to 4 carbon atoms,

in approximately equimolar amounts, if appropriate in the presence of adipolar aprotic diluent such as, for example, dimethylformamide,N-methylformanilide, N-methylpyrrolidone, dioxane, ethylene glycoldimethyl ether, ethylene glycol diethyl ether or hexamethylphosphorictriamide, but preferably without the addition of a diluent, attemperatures between 20° C. and 160° C., preferably between 100° C. and140° C.

Ketones of the formula (IV) are known or can be obtained in analogy toknown processes (cf., for example, U.S. Pat. No. 4,877,446; EP 301,393;EP 296,749; EP 289,913; DE 3,643,851; GB 2,120,664; DE 3,210,725; DE3,021,516).

Formaldehyde derivatives of the formula (V) are generally knowncompounds of organic chemistry.

The abovementioned definitions of the individual radicals of the formula(I) also apply analogously to the intermediates and precursors.

Suitable diluents for carrying out the process according to theinvention are inert organic solvents. These include, in particular,aliphatic, alicyclic or aromatic, optionally halogenated hydrocarbonssuch as, for example, benzine, benzene, toluene, xylene, chlorobenzene,petroleum ether, hexane, cyclohexane, dichloromethane, chloroform,carbon tetrachloride, ethers such as diethyl ether, dioxane,tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycoldiethyl ether, ketones such as acetone or butanone, nitriles such asacetonitrile or propionitrile, amides such as dimethylformamide,dimethylacetamide, N-methylformanilide, N-methylpyrrolidone orhexamethylphosphoric triamide, esters such as ethyl acetate, sulphoxidessuch as dimethyl sulphoxide, or alcohols such as methanol, ethanol andalso n- or i-propanol.

The process according to the invention is preferably carried out in thepresence of a suitable reaction auxiliary. Suitable reaction auxiliariesare all inorganic or organic bases which can be customarily be used. Thefollowing are preferably used: the hydrides, hydroxides, amides,alcoholates, carbonates or hydrogen carbonates of alkali metals, suchas, for example, sodium hydride, sodium amide, sodium hydroxide, sodiummethylate, sodium ethylate, potassium t-butylate, sodium carbonate orsodium hydrogen carbonate, and also tertiary amines such as, forexample, triethylamine, N,N-dimethylaniline, pyridine,N,N-dimethylaminopyridine, diazabicyclooctane (DABCO),diazabicyclononene (DBN) or diazabicycloundecene (DBU).

When carrying out the process according to the invention, the reactiontemperatures can be varied within a substantial range. In general, theprocess is carried out at temperatures between 20° C. and 140° C.,preferably at temperatures between 60° C. and 120C.

In general, the process according to the invention is carried out underatmospheric pressure. However, it is also possible to carry out theprocess according to the invention under increased or reduced pressure.

To carry out the process according to the invention, 0.8 to 1.5 moles,preferably 1.0 to 1.2 moles, of an enamine of the formula (III) and, ifappropriate, 1.0 to 2.0 moles, preferably 1.0 to 1.5 moles, of reactionauxiliary are generally employed per mole of 2-pyridylamidine salt ofthe formula (II).

The reaction is carried out and the reaction products are worked up andisolated by generally customary methods (cf. also the PreparationExamples).

The active compounds according to the invention have a powerful actionagainst pests and can be employed in practice for combating undesiredharmful organisms. The active compounds are particularly suitable foruse as plant protection agents, in particular as fungicides.

Fungicidal agents in plant protection are employed for combatingPlasmodiophoromycetes, Oomycetes, Chytridiomycetes, Zygomycetes,Ascomycetes, Basidiomycetes and Deuteromycetes.

Some causative organisms of fungal diseases which come under the genericnames listed above may be mentioned as examples, but not by way oflimitation: Pythium species, such as, for example, Pythium ultimum;Phytophthora species, such as, for example, Phytophthora infestans;

Pseudoperonospora species, such as, for example, Pseudoperonosporahumuli or Pseudoperonospora cubensis;

Plasmopara species, such as, for example, Plasmopara viticola;

Peronospora species, such as, for example, Peronospora pisi or P.brassicae;

Erysiphe species, such as, for example, Erysiphe graminis;

Sphaerotheca species, such as, for example, Sphaerotheca fuliginea;

Podosphaera species, such as, for example, Podosphaera leucotricha;

Venturia species, such as, for example, Venturia inaequalis;

Pyrenophora species, such as, for example, Pyrenophora teres or P.graminea (conidia form: Drechslera, syn: Helminthosporium);

Cochliobolus species, such as, for example, Cochliobolus satius (conidiaform: Drechslera, syn: Helminthosporium);

Uromyces species, such as, for example, Uromyces appendiculatus;

Puccinia species, such as, for example, Puccinia recondita;

Tilletia species, such as, for example, Tilletia caries;

Ustilago species, such as, for example, Ustilago nuda or Ustilagoavenae;

Pellicularia species, such as, for example, Pellicularia sasakii;

Pyricularia species, such as, for example, Pyricularia oryzae;

Fusarium species, such as, for example, Fusarium culmorum;

Botrytis species, such as, for example, Botrytis cinerea;

Septoria species, such as, for example, Septoria nodorum;

Leptosphaeria species, such as, for example, Leptosphaeria nodorum;

Cercospora species, such as, for example, Cercospora canescens;

Alternaria species, such as, for example, Alternaria brassicae and

Pseudocerosporella species, such as, for example, Pseudocercosporellaherpotrichoides.

The good toleration, by plants, of the active compounds, at theconcentrations required for combating plant diseases, permits treatmentof above-ground parts of plants, of vegetative propagation stock andseeds, and of the soil.

In this context, the active compounds according to the invention can beemployed with particularly good success for combating cereal diseasessuch as, for example, against the pathogen causing powdery cereal mildewon wheat or barley (Erysiphe graminis) or against the pathogen causingleaf spot on barley (Cochliobolus sativus) or against the pathogencausing leaf spot on wheat (Leptosphaeria nodorum) or against thepathogen causing net blotch on barley (Pyrenophora teres) or against thepathogen causing snow blight on cereals (Fusarium nivale) and againstother Fusarium pathogens such as, for example, Fusarium culmorum,moreover for combating diseases in rice growing such as, for example,against the pathogen causing rice blast disease (Pyricularia oryzae) oragainst the pathogen causing rice stem blight (Pellicularia sasakii) orfor combating diseases in viticulture such as, for example, against thepathogen causing mildew on grape vines (Uncinula necator).

In addition, mention must be made of a broad in-vitro action.

Besides, the active compounds are suitable for combating animal pests,preferably arthropods and nematodes, in particular insects and arachnidawhich are encountered in agriculture, in forests, in the protection ofstored products and of materials, and in the hygiene field, and havegood plant tolerance and favourable toxicity to warm-blooded animals.They are active against normally sensitive and resistant species andagainst all or some stages of development. The abovementioned pestsinclude:

From the order of the Isopoda, for example, Oniscus asellus,Armadillidium vulgare and Porcellio scaber. From the order of theDiplopoda, for example, Blaniulus guttulatus. From the order of theChilopoda, for example, Geophilus carpophagus and Scutigera spec. Fromthe order of the Symphyla, for example, Scutigerella mmaculata. From theorder of the Thysanura, for example, Lepisma saccharina. From the orderof the Collembola, for example, Onychiurus armaus. From the order of theOrthoptera, for example, Blatta orientalis, Periplaneta americana,Leucophaea maderae, Blattella germanica, Acheta domesticus, Gryllotalpaspp., Locusta migratoria migratorioides, Melanoplus differentialis andSchistocerca gregaria. From the order of the Dermaptera, for example,Forficula auricularia. From the order of the Isoptera, for example,Reticulitermes spp. From the order of the Anoplura, for example,Phylloxera vastatrix, Pemphigus spp., Pediculus humanus corporis,Haematopinus spp. and Linognathus spp. From the order of the Mallophaga,for example, Trichodectes spp. and Damalinea spp. From the order of theThysanoptera, for example, Hercinothrips femoralis and Thrips tabaci.From the order of the Heteroptera, for example, Eurygaster spp.,Dysdercus intermedius, Piesmaquadrata, Cimex lectularius, Rhodniusprolixus and Triatoma spp. From the order of the Homoptera, for example,Aleurodes brassicae, Bemisia tabaci, Trialeurodes vaporariorum, Aphisgossypii, Brevicoryne brassicae, Cryptomyzus ribis, Aphis fabae, Doralispomi, Eriosoma lanigerum, Hyalopterus arundinis, Macrosiphumavenae,Myzus spp., Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelisbilobatus, Nephotettix cincticep, Lecanium corni, Saissetia oleae,Laodelphax striatellus, Nilaparvata lugens, Aonidiella aurantii,Aspidiotus hederae, Pseudococcus spp. Psylla spp. From the order of theLepidoptera, for example, Pectinophora gossypiella, Bupalus piniarius,Cheimatobia brumata, Lithocolletis blancardella, Hyponomeuta padella,Plutella maculipennis, Malacosoma neustria, Euproctis chrysorrhoea,Lymantria app. Bucculatrix thurberiella, Phyllocnistis citrella, Agrotisspp., Euxoa spp., Feltia spp., Earias insulana, Heliothis spp.,Spodoptera exigua, Mamesra brassicae, Panolis flammea, Prodenia litura,Spodoptera spp., Trichoplusia ni, Carpocapsa pomonella, Pieris spp.,Chilo spp., Pyrausta nubilalis, Ephestia kuehniella, Galleriamellonella, Tineola bisselliella, Tinea pellionella, Hofmannophilapseudospretella, Cacoecia podana, Capua reticulana, Choristoneurafumiferana, Clysia ambiguella, Homona magnanima and Tortrix viridana.From the order of the Coleoptera, for example, Anobium punctatum,Rhizopertha dominica, Acanthoscelides obtectus, Acanthoscelidesobtectus, Hylotrupes bajulus, Agelastica alni, Leptinotarsadecemlineata, Phaedon cochleariae, Diabrotica spp., Psylliodeschrysocephala, Epilachna varive stis, Atomaria spp., Oryzaephilussurinamensis, Antho nomus spp., Sitophilus spp., Otiorrhynchus sulcatus,Cosmopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica,Dermestes spp., Trogoderma spp., Anthrenus spp., Attagenus spp., Lyctusspp., Meligethes aeneus, Ptinus spp., Niptus hololeucus, Gibbiumpsylloides, Tribolium spp., Tenebrio molitor, Agriotes spp., Cono derusspp., Melolontha melolontha, Amphimallon solsti tialis and Costelytrazealandica. From the order of the Hymenoptera, for example, Diprionspp., Hoplocampa spp., Lasius spp., Monomorium pharaonis and vespa spp.From the order of the Diptera, for example, Aedes spp., Anopheles spp.,Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphoraerythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp.,Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp.,Hypoderma spp., Tabanus spp., Tannia spp., Bibio hortulanus, Oscinellafrit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleaeand Tipula paludosa.

From the order of the Siphonaptera, for example, Xenopsylla cheopis andCeratophyllus spp.

Depending on their particular physical and/or chemical properties, theactive compounds can be converted to the customary formulations, such assolutions, emulsions, suspensions, powders, foams, pastes, granules,aerosols, natural and synthetic materials impregnated with activecompound, very fine capsules in polymeric substances and in coatingcompositions for seed, and formulations used with burning equipment,such as fumigating cartridges, fumigating cans, fumigating coils and thelike, as well as ULV cold mist and warm mist formulations.

These formulations are produced in a known manner, for example by mixingthe active compounds with extenders, that is, liquid solvents, liquefiedgases under pressure, and/or solid carriers, optionally with the use ofsurface-active agents, that is emulsifying agents and/or dispersingagents, and/or foam-forming agents. In the case of the use of water asan extender, organic solvents can, for example, also be used asauxiliary solvents. As liquid solvents, there are suitable in the main:aromatics, such as xylene, toluene, or alkylnaphthalenes, chlorinatedaromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes,chloroethylenes or methylene chloride, aliphatic hydrocarbons, such ascyclohexane or paraffins, for example mineral oil fractions, alcohols,such as butanol or glycol as well as their ethers and esters, ketones,such as acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethylformamide anddimethyl sulphoxide, as well as water; by liquefied gaseous extenders orcarriers are meant liquids which are gaseous at ambient temperature andunder atmospheric pressure, for example aerosol propellants, such ashalogenated hydrocarbons as well as butane, propane, nitrogen and carbondioxide; as solid carriers there are suitable: for example groundnatural minerals, such as kaolins, clays, talc, chalk, quartz,attapulgite, montmorillonite or diatomaceous earth, and ground syntheticminerals, such as highly disperse silica, alumina and silicates; assolid carriers for granules there are suitable: for example crushed andfractionated natural rocks such as calcite, marble, pumice, sepioliteand dolomite, as well as synthetic granules of inorganic and organicmeals, and granules of organic material such as sawdust, coconut shells,maize cobs and tobacco stalks; as emulsifying and/or foam-forming agentsthere are suitable: for example non-ionic and anionic emulsifiers, suchas polyoxyethylene fatty acid esters, polyoxyethylene fatty alcoholethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkylsulphates, arylsulphonates as well as albumen hydrolysis products; asdispersing agents there are suitable: for example lignin-sulphite wasteliquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospholipids, can be used in the formulations. Other additives can bemineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 per cent byweight of active compound, preferably between 0.5 and 90%.

When used as fungicides, the active compounds according to the inventioncan exist in the formulations as mixtures with other known activecompounds such as fungicides, insecticides, acaricides and herbicides,and as mixtures with fertilizers and growth regulators.

The active compounds can be used as such or in the form of theirformulations or the use forms prepared therefrom by further dilution,such as ready-to-use solutions, suspensions, wettable powders, pastes,soluble powders, dusts and granules. They are used in the customarymanner, for example by watering, spraying, atomizing, scattering,dusting, foaming, brushing on and the like. It is furthermore possibleto apply the active compounds by the ultra-low volume method or toinject the active compound formulation or the active compound itselfinto the soil. The seed of the plants can also be treated.

In the treatment of parts of plants, the active compound concentrationsin the use forms can be varied within a substantial range. They are, ingeneral, between 1 and 0.0001% by weight, preferably between 0.5 and0.001%.

In the treatment of seed, amounts of active compound of 0.001 to 50 gper kilogram of seed, preferably 0.01 to 10 g, are generally required.

For the treatment of soil, active compound concentrations of 0.00001 to0.1% by weight, preferably 0.0001 to 0.02% by weight, are required atthe place of action.

When used as insecticides, the active compounds according to theinvention can be present in their commercially available formulationsand in the use forms prepared from these formulations, as a mixture withother active compounds, such as insecticides, attractants, sterilizingagents, acaricides, nematicides, fungicides, growth-regulatingsubstances or herbicides. The insecticides include, for example,phosphates, carbamates, carboxylates, chlorinated hydrocarbons,phenylureas and substances produced by microorganisms, and others.

The active compounds according to the invention can furthermore bepresent in their commercially available formulations and in the useforms, prepared from these formulations, as a mixture with synergisticagents. Synergistic agents are compounds which increase the action ofthe active compounds, without it being necessary for the synergisticagent added to be active itself.

The active compound content of the use forms prepared from thecommercially available formulations can vary within wide limits. Theactive compound concentration of the use forms can be from 0.0000001 to95% by weight of active compound, preferably between 0.0001 and 1% byweight.

The compounds are employed in a customary manner appropriate for the useforms.

When used against hygiene pests and pests of stored products, the activecompounds are distinguished by an excellent residual action on wood andclay as well as a good stability to alkali on limed substrates.

PREPARATION EXAMPLES Example 1 ##STR134##

6.3 g (0.04 mol) of 2-pyridylamidine hydrochloride, 9.8 g (0.04 mol) of1-dimethylamino-4,4-dimethyl-5-(4-methylphenyl)-pent-1-en-3-one and 10.7g (0.05 mol) of sodium methylate are refluxed for 2 hours in 75 ml ofdry methanol. After cooling to room temperature, the mixture isacidified using glacial acetic acid and subsequently concentrated invacuo, the residue is stirred with water, the aqueous solution isdecanted off, the residue is stirred with ligroin and filtered, thefiltrate is concentrated in vacuo, and the residue is purified bychromatography (silica gel; eluent: ethyl acetate).

8.0 g (66% of theory) of2-(2-pyridyl)-4-[1,1-dimethyl-2-(4-methylphenyl)-ethyl]-pyrimidine areobtained as a highly viscous oil.

¹ H NMR (CDCl₃ /tetramethylsilane): δ=8.8 (d, 1H, J=6 Hz) ppm.

The following substituted pyridylpyrimidines of the general formula (I)are obtained analogously and following the general preparationinstructions:

    __________________________________________________________________________                                          (I)                                     Example No.                                                                          A        Ar            Physical properties                             __________________________________________________________________________     2                                                                                    ##STR135##                                                                             ##STR136##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)          3                                                                                    ##STR137##                                                                             ##STR138##   .sup.1 H NMR*.sup.) : 8.85(d, 1H, J=6Hz)         4                                                                                    ##STR139##                                                                             ##STR140##   .sup.1 H NMR*.sup.) : 8.9(d, 1H, J=6Hz)          5                                                                                    ##STR141##                                                                             ##STR142##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)          6                                                                                    ##STR143##                                                                             ##STR144##   .sup.1 H NMR*.sup.) : 8.9(d, 1H, J=6Hz)          7                                                                                    ##STR145##                                                                             ##STR146##   .sup.1 H NMR*.sup.) : 8.85(d, 1H, J=6Hz)         8                                                                                    ##STR147##                                                                             ##STR148##   .sup.1 H NMR*.sup.) : 8.9(d, 1H, J=6Hz)          9                                                                                    ##STR149##                                                                             ##STR150##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)         10                                                                                    ##STR151##                                                                             ##STR152##   .sup.1 H NMR*.sup.) : 8.85(d, 1H, J=6Hz)        11                                                                                    ##STR153##                                                                             ##STR154##   m.p.: 91-93° C.                          12                                                                                    ##STR155##                                                                             ##STR156##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)         13                                                                                    ##STR157##                                                                             ##STR158##   .sup.1 H NMR*.sup.) : 8.9(d, 1H, J=6Hz)         14                                                                                    ##STR159##                                                                             ##STR160##   .sup.1 H NMR*.sup.) : 8.9(d, 1H, J=6Hz)         15                                                                                    ##STR161##                                                                             ##STR162##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)         16                                                                                    ##STR163##                                                                             ##STR164##   .sup.1 H NMR*.sup.) : 8.85(d, 1H, J=6Hz)        17                                                                                    ##STR165##                                                                             ##STR166##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)         18                                                                                    ##STR167##                                                                             ##STR168##   .sup.1 H NMR*.sup.) : 8.8(d, 1H, J=6Hz)         19                                                                                    ##STR169##                                                                             ##STR170##   .sup.1 H NMR*.sup.) : 8.85(d, 1H, J=6Hz)        20                                                                                    ##STR171##                                                                             ##STR172##   .sup.1 H-NMR*.sup.) : δ=8.85(d, 1H;                                     J=6Hz)                                          21                                                                                    ##STR173##                                                                             ##STR174##   .sup.1 H-NMR*.sup.) : δ=8.8(d, 1H;                                      J=6Hz)                                          22                                                                                    ##STR175##                                                                             ##STR176##   m.p.: 75-77° C.                          23                                                                                    ##STR177##                                                                             ##STR178##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          24                                                                                    ##STR179##                                                                             ##STR180##   .sup.1 H-NMR*.sup.) : δ=8.85(d, 1H;                                     J=6Hz)                                          25                                                                                    ##STR181##                                                                             ##STR182##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          26                                                                                    ##STR183##                                                                             ##STR184##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          27                                                                                    ##STR185##                                                                             ##STR186##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          28                                                                                    ##STR187##                                                                             ##STR188##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          29                                                                                    ##STR189##                                                                             ##STR190##   m.p.: 91-94° C.                          30                                                                                    ##STR191##                                                                             ##STR192##   .sup.1 H-NMR*.sup.) : δ=9.0(d, 1H;                                      J=6Hz)                                          31                                                                                    ##STR193##                                                                             ##STR194##   .sup.1 H-NMR*.sup.) : δ=8.95(d, 1H;                                     J=6Hz)                                          32                                                                                    ##STR195##                                                                             ##STR196##   .sup.1 H-NMR*.sup.) : δ=8.95(d, 1H;                                     J=6Hz)                                          33                                                                                    ##STR197##                                                                             ##STR198##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          34                                                                                    ##STR199##                                                                             ##STR200##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          35                                                                                    ##STR201##                                                                             ##STR202##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          36                                                                                    ##STR203##                                                                             ##STR204##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          37                                                                                    ##STR205##                                                                             ##STR206##   .sup.1 H-NMR*.sup.) : δ=8.95(d, 1H;                                     J=6Hz)                                          38                                                                                    ##STR207##                                                                             ##STR208##   .sup.1 H-NMR*.sup.) : δ=8.95(d, 1H;                                     J=6Hz)                                          39                                                                                    ##STR209##                                                                             ##STR210##   .sup.1 H-NMR*.sup.) : δ=8.8(d, 1H;                                      J=6Hz)                                          40                                                                                    ##STR211##                                                                             ##STR212##   .sup.1 H-NMR*.sup.) : δ=8.9(d, 1H;                                      J=6Hz)                                          41                                                                                    ##STR213##                                                                             ##STR214##   .sup.1 H-NMR*.sup.) : δ=8.9(d,   1H;                                    J=6Hz)                                          __________________________________________________________________________     *.sup.) The .sup.1 H NMR spectra were recorded in deuterochloroform           (CDCl.sub.3) or hexadeuterodimethylsulfoxid (DMSOd.sub.6) with                tetramethylsilane (TMS) as the internal standard. The figures indicate th     chemical shift as value in ppm.                                          

Example III- 1 ##STR215##

33.3 g (0. 175 mol) of 4-(4-methylphenyl)-3,3-dimethylbutan-2-one and22.9 g (0.193 mol) of dimethylformamide dimethyl acetal are combined andthe mixture is refluxed for 2 hours. After cooling to room temperature,the mixture is concentrated in vacuo, and the residue is stirred withligroin, filtered off with suction and dried.

14.7 g (34% of theory) of1-dimethylamino-4,4-dimethyl-(5-(4-methylphenyl)-pent-1-en-3-one ofmelting point 74° to 76° C. are obtained.

Preparation of the compound:

Example IV-1 ##STR216##

To 84 g (1.5 mol) of powdered potassium hydroxide and 4.8 g (0.015 mol)of tetrabutylammoniumbromide in 125 ml of dry toluene there are addeddropwise with stirring at room temperature first 51.6 g (0.6 mol) ofmethyl isopropyl ketone and subsequently 70.3 g (0.5 ml) of4-methylbenzyl chloride in 125 ml of dry toluene, and the mixture isthen stirred at room temperature for 16 hours. For working up, thereaction mixture is treated with water, the organic phase is separatedoff, dried over sodium sulphate and concentrated, and the concentrate isdistilled in vacuo.

36.1 g (38% of theory) of 3,3-dimethyl-4-(4-methylphenyl)-butan-2-oneare obtained, boiling point 98° to 101° C. at 5 mbar.

The following enamines of the general formula (III) are obtainedanalogously and following the general preparation instructions:

    __________________________________________________________________________     ##STR217##                          (III)                                    Example No.                                                                          Ar            A        Physical properties                             __________________________________________________________________________    III-2                                                                                 ##STR218##                                                                                  ##STR219##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-3                                                                                 ##STR220##                                                                                  ##STR221##                                                                            m.p.: 63-66° C.                          III-4                                                                                 ##STR222##                                                                                  ##STR223##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-5                                                                                 ##STR224##                                                                                  ##STR225##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-6                                                                                 ##STR226##                                                                                  ##STR227##                                                                            .sup.1 H NMR*.sup.) : 5.3(d, 1H, J=12Hz)        III-7                                                                                 ##STR228##                                                                                  ##STR229##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-8                                                                                 ##STR230##                                                                                  ##STR231##                                                                            .sup.1 H NMR*.sup.) : 5.3(d, 1H, J=12Hz)        III-9                                                                                 ##STR232##                                                                                  ##STR233##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-10                                                                                ##STR234##                                                                                  ##STR235##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-11                                                                                ##STR236##                                                                                  ##STR237##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-12                                                                                ##STR238##                                                                                  ##STR239##                                                                            m.p.: 99-101° C.                         III-13                                                                                ##STR240##                                                                                  ##STR241##                                                                            m.p.: 79-81° C.                          III-14                                                                                ##STR242##                                                                                  ##STR243##                                                                            m.p.: 54-56° C.                          III-15                                                                                ##STR244##                                                                                  ##STR245##                                                                            .sup.1 H NMR*.sup.) : 5.25(d, 1H, J=12Hz)       III-16                                                                                ##STR246##                                                                                  ##STR247##                                                                            .sup.1 H NMR*.sup.) : 5.2(d, 1H, J=12Hz)        III-17                                                                                ##STR248##                                                                                  ##STR249##                                                                            .sup.1 H NMR*.sup.) : 5.2(d, 1H, J=12Hz)        III-18                                                                                ##STR250##                                                                                  ##STR251##                                                                            .sup.1 H NMR*.sup.) : 5.2(d, 1H, J=12Hz)        III-19                                                                                ##STR252##                                                                                  ##STR253##                                                                            .sup.1 H NMR*.sup.) : 5.2(d, 1H, J=12Hz)        III-20                                                                                ##STR254##                                                                                  ##STR255##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-21                                                                                ##STR256##                                                                                  ##STR257##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-22                                                                                ##STR258##                                                                                  ##STR259##                                                                            .sup.1 H-NMR*.sup.) : δ=5.3(d,  1H;                                     J=12Hz)                                         III-23                                                                                ##STR260##                                                                                  ##STR261##                                                                            m.p.: 121-123° C.                        III-24                                                                                ##STR262##                                                                                  ##STR263##                                                                            .sup.1 H-NMR*.sup.) : δ=5.25(d,  1H;                                    J=12Hz)                                         III-25                                                                                ##STR264##                                                                                  ##STR265##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-26                                                                                ##STR266##                                                                                  ##STR267##                                                                            .sup.1 H-NMR*.sup.) : δ=5.35(d,  1H;                                    J=12Hz)                                         III-27                                                                                ##STR268##                                                                                  ##STR269##                                                                            m.p.: 99-102° C.                         III-28                                                                                ##STR270##                                                                                  ##STR271##                                                                            .sup.1 H-NMR*.sup.) : δ=5.25(d,  1H;                                    J=12Hz)                                         III-29                                                                                ##STR272##                                                                                  ##STR273##                                                                            .sup.1 H-NMR*.sup.) : δ=5.25(d,  1H;                                    J=12Hz)                                         III-30                                                                                ##STR274##                                                                                  ##STR275##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-31                                                                                ##STR276##                                                                                  ##STR277##                                                                            .sup.1 H-NMR*.sup.) : δ=5.3(d,  1H;                                     J=12Hz)                                         III-32                                                                                ##STR278##                                                                                  ##STR279##                                                                            .sup.1 H-NMR*.sup.) : δ=5.15(d,  1H;                                    J=12Hz)                                         III-33                                                                                ##STR280##                                                                                  ##STR281##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-34                                                                                ##STR282##                                                                                  ##STR283##                                                                            m.p.: 71-74° C.                          III-35                                                                                ##STR284##                                                                                  ##STR285##                                                                            .sup.1 H-NMR*.sup.) : δ=5.35(d,  1H;                                    J=12Hz)                                         III-36                                                                                ##STR286##                                                                                  ##STR287##                                                                            .sup.1 H-NMR*.sup.) : δ=5.3(d,  1H;                                     J=12Hz)                                         III-37                                                                                ##STR288##                                                                                  ##STR289##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-38                                                                                ##STR290##                                                                                  ##STR291##                                                                            .sup.1 H-NMR*.sup.) : δ=5.3(d,  1H;                                     J=12Hz)                                         III-39                                                                                ##STR292##                                                                                  ##STR293##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-40                                                                                ##STR294##                                                                                  ##STR295##                                                                            .sup.1 H-NMR*.sup.) : δ=5.32(d,  1H;                                    J=12Hz)                                         III-41                                                                                ##STR296##                                                                                  ##STR297##                                                                            .sup.1 H-NMR*.sup.) : δ =5.2(d,  1H;                                    J=12Hz)                                         III-42                                                                                ##STR298##                                                                                  ##STR299##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-43                                                                                ##STR300##                                                                                  ##STR301##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-44                                                                                ##STR302##                                                                                  ##STR303##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         III-45                                                                                ##STR304##                                                                                  ##STR305##                                                                            .sup.1 H-NMR*.sup.) : δ=5.2(d,  1H;                                     J=12Hz)                                         __________________________________________________________________________     *.sup.) The .sup.1 H NMR spectra were recorded in deuterochloroform           (CDCl.sub.3) with tetramethylsilane (TMS) as the internal standard. The       figures indicate the chemical shift as δ value in ppm.             

Use Examples

In the Use Examples which follow, the compounds listed below wereapplied as comparison substances: ##STR306##2-(6-phenyl-2-pyridyl)-4-chloro-6-methyl-pyrimidine (disclosed in EP259,139 ) ##STR307##2-(6-methyl-2-pyridyl)-4-(2-methylphenyl)-pyrimidine (disclosed in EP270,362 ) ##STR308##2-(6-methyl-2-pyridyl)-4-hydroxy-6-phenyl-pyrimidine (disclosed in EP270,362)

Example A

Cochliobolus sativus test (barley)/protective

Solvent: 100 parts by weight of dimethylformamide Emulsifier: 0.25 partsby weight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amounts of solvent andemulsifier, and the concentrate is diluted with water to the desiredconcentration.

To test for protective activity, young plants are sprayed with thepreparation of active compound until dew-moist. After the spray coatinghas dried on, the plants are sprayed with a conidia suspension ofCochliobolus sativus. The plants remain in an incubation cabinet for 48hours at 20° C. and 100% relative atmospheric humidity.

The plants are placed in a greenhouse at a temperature of approx. 20° C.and a relative atmospheric humidity of approx. 80%.

The test is evaluated 7 days after inoculation.

The compounds of the Preparation Examples 5, 6, 8, 9, 10 and 11 show adegree of activity of 81-100% at an active compound concentration of250ppm. The comparison examples (A), (B) and (C) show at the same activecompound concentration no activity.

Example B

Erysiphe test (wheat)/protective

Solvent: 100 parts by weight of dimethylformamide Emulsifier: 0.25 partsby weight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amounts of solvent andemulsifier, and the concentrate is diluted with water to the desiredconcentration.

To test for protective activity, young plants are sprayed with thepreparation of active compound until dew-moist. After the spray coatinghas dried on, the plants are dusted with spores of Erysiphe graminisf.sp. tritici.

The plants are placed in a greenhouse at a temperature of approx. 20° C.and a relative atmospheric humidity of approx. 80% to favour thedevelopment of mildew pustules.

The test is evaluated 7 days after inoculation.

The compounds of the Preparatton Examples 2 and 7 show a degree ofactivity of 100% at an active compound concentration of 250 ppm. Thecomparison example (B) shows no activity.

Example C

Uncinula test (grapevine)/protective

Solvent: 4.7 parts by weight of acetone Emulsifier: 0.3 parts by weightof alkyl-aryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amounts of solvent andemulsifier, and the concentrate is diluted with water to the desiredconcentration.

To test for protective activity, young plants are sprayed with thepreparation of active compound until dripping wet. After the spraycoating has dried on, the plants are dusted with conidia of the fungusUncinula necator.

The plants are subsequently placed in a greenhouse at 23° to 24° C. anda relative atmospheric humidity of approx. 75%.

The test is evaluated 14 days after inoculaton

The compounds of the Preparation Examples 1, 4, 5, 7, 8, 9, 10, 12, 13,14, 15, 16, 17, 18 and 19 show a degree of activity of 82°-100% at anactive compound concentration of 10 ppm. The comparison example (A)shows a degree of activity of 69% at the same active compoundconcentration.

Example D

Plutella test

Solvent: 7 parts by weight of dimethylformamide Emulsifier: 1 part byweight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted with waterto the desired concentration.

Cabbage leaves (Brassica oleracea) are treated by dipping into thepreparation of active compound of the desired concentration and areinfected with caterpillars of the cabbage moth (Plutella maculipennis)while the leaves are moist.

After the specified time, the destruction is determined in %. 100%denotes that all caterpillars have been killed; 0% denotes that nocaterpillars have been killed.

In this test, for example, the compound (2) of the Preparation Examplesshows a degree of mortality of 100% at an active compound concentrationof 0.1%.

Example E

Nephotettix text

Solvent: 7 parts by weight of dimethylformamide Emulsifier: 1 part byweight of alkylaryl polyglycol ether

To prepare a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted with waterto the desired concentration.

Rice seedlings (Oryza satira) are treated by dipping into the activecompound preparation of the desired concentration and are infested withlarvae of the green rice cicada (Nephotettix cincticeps) while theseedlings are moist.

After the specified time, the destruction is determined in %. 100%denotes that all cicadas have been killed; 0% denotes that no cicadashave been killed.

In this test, for example, the compound (2) of the Preparation Examplesshows a degree of mortality of 100% at an active compound concentrationof 0.1%.

We claim:
 1. A pyridylpyrimidine compound of the formula ##STR309## in which A represents a radical of the formula ##STR310## where R represents straight-chain or branched alkyl having 1 to 4 carbon atoms,X represents oxygen or sulphur and Ar represents phenyl which is optionally monosubstituted to pentasubstituted by identical or different substituents, wherein the substituents are halogen, cyano, nitro, straight-chain or branched alkyl, straight-chain or branched alkoxy or straight-chain or branched alkylthio, each having 1 to 4 carbon atoms in the alkyl moieties, straight-chain or branched halogenoalkyl, straight-chain or branched halogenoalkoxy or straight-chain or branched halogenoalkylthio, each having 1 to 4 carbon atoms in the alkyl moiety and 1 to 9 identical or different halogen atoms, straight-chain or branched alkoxycarbonyl or alkoxyiminoalkyl, each having 1 to 4 carbon atoms in the individual alkyl moieties, or phenyl which is optionally monosubstituted to pentasubstituted by identical or different substituents from the series group consisting of halogen and straight-chain or branched alkyl having 1 to 4 carbon atoms.
 2. A pyridylpyrimidine compound according to claim 1, in whichA represents a radical of the formula ##STR311## where R in each case represents methyl or ethyl, X represents oxygen or sulphur and Ar represents phenyl which is optionally monosubstituted to trisubstituted by identical or different substituents, wherein the substituents are fluorine, chlorine, bromine, cyano, nitro, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, methoxy, ethoxy, n- or i-propoxy, methylthio, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, methoxycarbonyl, ethoxycarbonyl, methoxyiminomethyl, ethoxyiminomethyl, methoxyiminoethyl, ethoxyiminoethyl, or phenyl which is optionally monosubstituted to trisubstituted by identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, methyl and ethyl.
 3. A composition for combatting fungi, arthropods, or menatodes which comprises an effective amount of a compound according to claim 1 and an inert carrier.
 4. A method for combatting fungi, arthropods or menatodes which comprises applying thereto an effective amount of a compound of claim
 1. 5. A process for the preparation of a pyridylpyrimidine compound of the formula ##STR312## in which A represents a radical of the formula ##STR313## where R represents straight-chain or branched alkyl having 1 to 4 carbon atoms,X represents oxygen or sulphur and Ar represents phenyl which is optionally monosubstituted to pentasubstituted by identical or different substituents, wherein the substituents are halogen, cyano, nitro, straight-chain or branched alkyl, straight-chain or branched alkoxy or straight-chain or branched alkylthio, each having 1 to 4 carbon atoms in the alkyl moieties, straight-chain or branched halogenoalkyl, straight-chain or branched halogenoalkoxy or straight-chain or branched halogenoalkylthio, each having 1 to 4 carbon atoms in the alkyl moiety and 1 to 9 identical or different halogen atoms, straight-chain or branched alkoxycarbonyl or alkoxyiminoalkyl, each having 1 to 4 carbon atoms in the individual alkyl moieties, or phenyl which is optionally monosubstituted to pentasubstituted by identical or different substituents from the series group consisting of halogen and straight-chain or branched alkyl having 1 to 4 carbon atoms,characterised in that 2-pyridylamidine salts of the formula (II) ##STR314## in which Y represents the anion of an inorganic mineral acid, are reacted with examines of the formula (III) ##STR315## in which Ar and A have the abovementioned meaning, if appropriate in the presence of a diluent and if appropriate in the presence of a reaction auxiliary. 